Female Predominance of Long-QT Syndrome Examined
Study sheds light on female predominance, transmission distortion in long-QT syndrome
FRIDAY, Dec. 29 (HealthDay News) -- Transmission distortion among people with long-QT syndrome is due to positive selection of the mutated allele, researchers report in the Dec. 28 issue of the New England Journal of Medicine.
Medea Imboden, Ph.D., of the University of Zurich in Switzerland, and colleagues studied the distribution of alleles for the long-QT syndrome in 484 nuclear families with type 1 disease and 269 nuclear families with type 2 disease, all of whom had fully genotyped families.
The investigators found that positive selection of the mutated alleles that cause the long-QT syndrome leads to transmission distortion, with increased proportions of mutation carriers among the offspring of affected families. Moreover, the probability of inheriting a mutation for the long-QT syndrome was higher than expected according to mendelian inheritance. The study also showed that daughters are favored during maternal transmission.
"The skewed segregation of the mutation from mothers to their daughters might contribute substantially to the observed female predominance in the long-QT syndrome," the study authors conclude.